open-consul/logging/logfile.go
Daniel Nephin 5665f27b27 logging: improve tests
Standardize naming
Use stricter assertions and reduce boilerplate to make the intent of the tests more obvious.

Also explicitly sort the filenames so that the correct files are pruned,
and so that the tests can not flake.
2020-11-23 14:41:54 -05:00

142 lines
3.2 KiB
Go

package logging
import (
"fmt"
"os"
"path/filepath"
"sort"
"strconv"
"strings"
"sync"
"time"
)
var (
now = time.Now
)
//LogFile is used to setup a file based logger that also performs log rotation
type LogFile struct {
//Name of the log file
fileName string
//Path to the log file
logPath string
//Duration between each file rotation operation
duration time.Duration
//LastCreated represents the creation time of the latest log
LastCreated time.Time
//FileInfo is the pointer to the current file being written to
FileInfo *os.File
//MaxBytes is the maximum number of desired bytes for a log file
MaxBytes int
//BytesWritten is the number of bytes written in the current log file
BytesWritten int64
// Max rotated files to keep before removing them.
MaxFiles int
//acquire is the mutex utilized to ensure we have no concurrency issues
acquire sync.Mutex
}
func (l *LogFile) fileNamePattern() string {
// Extract the file extension
fileExt := filepath.Ext(l.fileName)
// If we have no file extension we append .log
if fileExt == "" {
fileExt = ".log"
}
// Remove the file extension from the filename
return strings.TrimSuffix(l.fileName, fileExt) + "-%s" + fileExt
}
func (l *LogFile) openNew() error {
fileNamePattern := l.fileNamePattern()
createTime := now()
newfileName := fmt.Sprintf(fileNamePattern, strconv.FormatInt(createTime.UnixNano(), 10))
newfilePath := filepath.Join(l.logPath, newfileName)
// Try creating a file. We truncate the file because we are the only authority to write the logs
filePointer, err := os.OpenFile(newfilePath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0640)
if err != nil {
return err
}
l.FileInfo = filePointer
// New file, new bytes tracker, new creation time :)
l.LastCreated = createTime
l.BytesWritten = 0
return nil
}
func (l *LogFile) rotate() error {
// Get the time from the last point of contact
timeElapsed := time.Since(l.LastCreated)
// Rotate if we hit the byte file limit or the time limit
if (l.BytesWritten >= int64(l.MaxBytes) && (l.MaxBytes > 0)) || timeElapsed >= l.duration {
l.FileInfo.Close()
if err := l.pruneFiles(); err != nil {
return err
}
return l.openNew()
}
return nil
}
func (l *LogFile) pruneFiles() error {
if l.MaxFiles == 0 {
return nil
}
pattern := filepath.Join(l.logPath, fmt.Sprintf(l.fileNamePattern(), "*"))
matches, err := filepath.Glob(pattern)
if err != nil {
return err
}
switch {
case l.MaxFiles < 0:
return removeFiles(matches)
case len(matches) < l.MaxFiles:
return nil
}
sort.Strings(matches)
last := len(matches) - l.MaxFiles
return removeFiles(matches[:last])
}
func removeFiles(files []string) error {
for _, file := range files {
if err := os.Remove(file); err != nil {
return err
}
}
return nil
}
// Write is used to implement io.Writer
func (l *LogFile) Write(b []byte) (n int, err error) {
l.acquire.Lock()
defer l.acquire.Unlock()
// Create a new file if we have no file to write to
if l.FileInfo == nil {
if err := l.openNew(); err != nil {
return 0, err
}
}
// Check for the last contact and rotate if necessary
if err := l.rotate(); err != nil {
return 0, err
}
l.BytesWritten += int64(len(b))
return l.FileInfo.Write(b)
}